Blind stitch sewing machine



1934- c. w. MUELLER BLIND STITCH SEWING MACHINE Filed Feb. 24, 1952 5Sheets-Sheet 1 INVENTOR C M/[fueller ATTORNEY Dec. 18, 1934 c w MUELLERI 1,984,755

BLIND STITCH SEWING MACHINE Filed Feb. 24, 1952 3 Sheets-Sheet 2 Dec.18, 1934. c. w. MUELLER BLIND STITCH SEWING MACHINE Filed Feb. 24, 1932I5 Sheets-Sheet 5 ulllllllllllllljlgln In w Patented Dec. 18, 1934UNITED STATES 1,984,755 BLIND STITCH SEWING MACHINE Charles W. Mueller,St. Louis, Mo., assignor to Lewis Invisible Stitch Machine Company, St.Louis, Mo., a corporation of Maine Application February 24, 1932, SerialNo. 594,930 I 15 Claims. (Cl. 112-178) This invention relates to new anduseful improvements in blind'stitch sewing machines generally, althoughmore particularly to machines for blind stitching hems along the bottomsof skirts and on other articles of wearing apparel, and embodies certainimprovements and changes over my co-pending application Serial No. '75,-891, filed November 18, 1931, which discloses a flat bed type of machinesuch as is shown in my prior Patent 1,764,573, June 17, 1930.

The present invention is shown as applied to a cylinder or work arm typeof machine such as is illustrated in my prior Patents 1,539,399, May 26,1925 and 1,791,220, February 3, 1931,

Among the several objects of my invention are,

to provide in a blind stitch sewing machine, a presser foot having aslot ending rearwardly from the front edge thereof, and through whichthe hem fold is projected upwardly into needle penetrating position, anda hemmer mounted in front of the foot with its nose located directly infront of the slot whereby the length of the hem fold between the needleand the nose of the folder will be reduced to a minimum and the hem willbe caught by the needle before it can possibly unfold; to provide such ahemmer which can be easily adjusted laterally, vertically, and also backand forth, relative to the stationary presser foot whereby the nose ofthe hemmer may be properly positioned relativ'eto the point of needlepenetration regardless of the weight of material being. hemmed; toprovide a bottom and top feedingmeans for insuring the proper feedingaction to the hemmed material, and to support the hemmer on a flat workplate which is mounted on the machine frame for vertical movements andalso for back and forth movements.

With these and other objects in view which will more fully appear, thenature of the invention will be more clearly understood ,by followingthe description, the appended claims, and the several views illustratedin the accompanying drawings.

In the drawings:

Figure 1 is a front elevation of a sewing machine embodying myinvention. I

Figure 2 is a left hand elevation thereof.-

Figure 3 is a horizontal sectional view taken directly above thestationary presser foot and showing particularly the relation betweenthe hemmer and the foot and the means forsupporting the hemmer on thework support, as well as the means for mounting the work support on thestandard.

Figure 4 is a vertical longitudinal sectional view thereof.

Figure 5 is an enlarged top plan view of the work'pressing mechanismwhich is disposed directly below the presser foot.

Figure 6 isan enlarged detailed horizontal view'showing particularly therelation between the stationarytpresser foot and the hemmer.

Figure 7 is a bottom plan view of the foot.

Figure 8 is a' perspective view of the main feed dog,

Figure 9 is'a perspective view of the'auxiliary spring pressed feed dog,and

Figure 10 is a vertical section taken through the feed dog.

Referring to the drawings, my invention is disclosed as beingillustrated in the blind stitch sewing machine of the well-known Lewistype, and includes a base A, a post or standard B, an overhanging arm Cwhich supports at its outer end a stitching head D, and a work arm Ewhich projects laterally from the standard B and terminates at its freeend under the stitching head D.

Rigidly attached to the lower end of the stitching headjD is a presserfoot 5. Thefront right hand corner portion of the foot is cut away as at6 which forms a resultant transverse front wall or edge '7. The foot isprovided centrally with a slot 8 which extends rearwardly from the frontedge 7. The presser foot is also provided in rear of the slot 8 with atop feed slot '9, and at the left of the slot 8 with alooper clearanceslot 10. 7

As previously stated my invention is adapted to form a hem fold in afabric and blind stitch said hem fold. In the present instance I havedisclosed a single thread stitch forming mechanism for blind stitchingthe hem, but I wish it tobe understood that any other stitch formingmechanism may be employed if desired. In the present instance'a singlethread stitch forming mechanism includes a curved needle 11 which isfixed to an oscillatory needle arm 12 which is driven from the mainshaft 13, journaled in the overhanging arm C through'th'e medium ofdriving connections'indicated as a whole by the reference numeral 14.The needle llhas its penetratingmovement across the line of the feed ofthe material and in aplane directly above the slot 8' of the foot.Cooperating with the needle 11 to form a line of single thread chainstitches is a looper 15 Which'is rnounted on the stitching head D andhas itsmovements imparted thereto from the 'main shaft 13 through themedium of driving connections indicated as a whole by the referencenumeral 16, the looper during each cycle being received by the looperclearance slot 10.

Disposed above the work arm E and pivotally and detachably supported onthe standard A is a flat work plate 1'7. The right hand end of the plate17 is provided with front and rear and downwardly extending legs 18, l9which embrace the standard A. Pivot screws 20, 21 are threadably engagedin the legs 18, 19 and the inner ends of these screws are pivotallymounted in bearing seats 22, 23 respectively formed in the front andrear faces of the standard A. Clamping nuts 24, 25 are respectivelyassociated with the pivot screws and co-operate with the legs to retainthe screws in adjusted positions. The work plate 17 extends to the leftof thepresser foot 5 and is provided with an opening 26 directlythereunder, said opening extending forwardly from the rear edge of theplate. Rigidly connected to the upper face of the work arm E is ananchor or post 27. Preferably this post comprises a threaded shank whichhas threaded engagement in an opening 28 formed in the work arm E, andthe upper end of the shank is provided with a head 29. A clamping nut 30has threaded engagement with the shank and cooperates with the arm E toclamp the post rigid ly to the arm in different positions of verticaladjustment. Formed in the work plate 17 at one side of the post 27 is athreaded opening 31, and engaged in this opening for verticaladjustments is an adjusting post 32 which projects downwardly below thelower face of the work plate 1'? and is provided on its projectingendwith a peripheral groove 33 for receiving the head 29 of the rigid post2'7. The adjusting post 32 projects above the work plate 17 and fixed tothe upper end thereof is a knurled head 34. Cooperating with the knurledhead 34 is a spring detent 35 which is mounted on the work plate 17 andfunctions to retain the adjusting post 32 in different verticalpositions. It will therefore be seen that by turning the adjusting post32 the work plate 17 may be swung vertically about the pivot screws 20,21 and that by means of the detent 35 the adjusting post 32 will beretained against accidental rotation and consequently the work plate 17will be retained in a vertically adjusted position. It will also beobserved that the work plate 17 may be adjusted forwardly or backwardlyby loosening one of the pivot screws and tightening the other, thisbackward and forward movement being permitted by reason of the adjustingpost 32 being disposed at one side of the anchoring post 2'7.

A hemmer 36 is rigidly mounted on the work plate 17 at a point in frontof the presser foot 5, the nose of the hammer projecting rearwardly intothe space formed by the cut out portion 6 of the foot and having itsdelivery end located directly in front of the slot 8 of said foot. Thehemmer 36 is provided with a laterally extending supporting arm 37 whichunderlies an extension arm 38 and is detachably secured thereto by meansof screws 39. The extension arm 38 is seated between the front and rearguide ribs 40, 40 integrally formed on the upper surface of the workplate 1'7 and located slightly to the right of the presser foot 5. Aclamping screw 41 passes through an unthreaded opening formed in theextension arm 38 and has threaded engagement in the work plate 1'7. Theopening in the arm 38 having a slightly larger diameter than thediameter of the clamping screw so as to permit said arm 38 together withthe hammer 36 being laterally adjusted. The guide ribs 40, 4e aredisposed in parallel planes extending at right angles to thelongitudinal axis of the presser foot. Consequently the hemmer may beadjusted laterally relative to the slot 8 within the limits defined bythe clamping screw 41 and the. opening in the extension arm 38 throughwhich the screw passes.

Disposed below the presser foot 5 and co-opcrating therewith to feed thehemmed fabric rearwardly past the needle is a work pressing mechanismwhich includes a work clamp F, a 4- motion main feed dog G, a 4 motionauxiliary feed dog H and a vertically reciprocatory ridge formingelement I. The 4-motion main feed dog G has itsup and down and backwardand forward movements imparted to it from the main shaft 13 through themedium of connections which are indicated as a whole by the referencenumeral 42, and which connections are disclosed in my prior Patent1,791,220 referred to above, and further description thereof is thoughtto be unnecessary. In the present invention however the feed dog G isprovided with. a supporting shank 43 to which a relatively long feedsection 44 is integrally attached. This feed dog operates in a feed slot45 formed in the work clamp F which is disposed at the left. of theridge forming element I and extends from a point in front of the slot 8of the presser foot we point in rear thereof. Thus the main feed dogsection 44. engages the body of the fabric and feeds the same rearwardlyfrom the hemmer 36 past the ridge forming element I. Rigidly connectedto the shank 43 of the'main feed dog G adjacent the rear end thereof isa laterally extending arm 46. A vertical shank 47 isintegral with theright hand edge of the arm 46 and forms a resultant stop shoulder 48.The 4-motion auxiliary feed dog H is connected to the main feed dog Gand co -operates directly with the hem fold. of the material to feed thehem and intermittently clamp said hem against the presser foot duringthe setting of the stitches to thereby prevent the hem from being curledor rolled. Furthermore this auxiliary feed dog H is yieldably mountedwhereby hem folds of different thicknesses due to different weights ofmaterials may be automatically accommodated. The auxiliary feed dog Hincludes a supporting bar and a relatively short and narrow feed section51 which is integrally or otherwise fixedly secured to the bar. This baris located above the arm 46 and below the stop shoulder 48, and the rearend of the bar is pivotally connected to the shank 47 by a horizontalpivot screw 52. The rear end of the feed section 51 is provided with alimiting stop 53 which is adapted to engage the stop shoulder 48 andthereby limit the upward movement of the auxiliary feed dog rela tive tothe main feed dog. A coiled spring 54 has its upper end seated in arecess formed in the barc50 and the lower end of this spring rests uponthe arm 45. Thus the spring 54 which is disposed in front of the pivotscrew 52 yieldably retains the stop 53 against the stop shoulder 48.Thus the auxiliary feed section 51 yieldably engages the outer foldedportion of the hem at the right of the line of needle penetrations andcooperates with the presser foot to clamp the hem therebetween, andthereby not only prevents the setting of the stitches from curling orrolling the hem, but also permits materials of different weights to befed properly.

The work clamp F is caused to reciprocate vertically in timed relationwith the main feed dog G, in the usual manner, whereby the work clamp islowered during the feeding stroke of the feed dog and elevated, intoclamping engagement with the presser foot during the return stroke ofthe feed dog in order to clamp the material against the penetratingstroke of the needle.

The ridge forming element I is in the form of a plunger which isreciprocated vertically in timed relation to the needle and to the mainfeed dog in the usual manner, whereby the plunger will be at the lowerend of its stroke during the feeding motion of the feed dog and will beelevated during the idle portion of the feed movement to project a ridgeof hemmed material upwardly through the slot 8-of the presser foot intoneedle penetrating position, whereby the needle will enter the bodyfabric and the inner edge of the hem as will be readily understood.

Co-operating with the lower feeds G and H to feed the hemmed materialrearwardly is a 4- motion top feed dog J which operates in the top feedslot 9 of the presser foot. This top feed dog is mounted on the lowerend of a lever 55 and has a sliding pivotal connection intermediate itsends in a guide 56 which is journaled in a horizontal bearing 57 fixedto the stitching head D. The upper end of the lever 55 engages aneccentric 58 fixed to the main shaft 13. Consequently, during eachrotation of the main shaft the top feed lever 55 is oscillated about thehorizontal bearing 57 and is also raised and lowered by reason of thelever sliding longitudinally through the guide 56, the component ofthese 4-motions producing a substantially elliptical path of travel.

From the foregoing it will be observed that I have provided a blindstitch sewing machine for stitching a hem fold along the edge of afabric; that by reason of the front right hand corner of the presserfoot being cut away the nose of the folder can be placed directly infront of the rearwardly extending slot 8 in the foot through which theridge of hemmed material is upwardly projected into the path of needlepenetration; that the hemmer is capableof being adjusted laterallyrelative to theslot 8, and also adjusted vertically as well asbackwardly and forwardly relatively to the foot; that the folder ismounted upon a work plate which in turn is mounted on the frame of themachine for vertical adjustments and also for backward and forwardadjustments; that the lower feed mechanism includes a verticallyyieldable auxiliary feed dog which co-operates with the hem fold of thematerial to feed the same rearwardly regardless of the weight of thematerial being employed, and that a top feed mechanism co-operates withthe lower feed mechanism to feed the hem fold rearwardly.

I claim:-

1. In a blind stitch sewing machine, the combination with a stationarypresser foot having a slot extending rearwardly from the front endthereof, of a feeding means co-operating with the foot to feed thematerial rearwardly, a stitch forming mechanism including areciprocatory needle disposed above the slot in the foot, a hemmerlocated in front of the foot and having its nose directly in front ofthe slot in saidfoot, a ridge forming element for projecting a ridge ofhemmed material upwardly through the slot in the foot and into the pathof the needle, and means for supporting the hemmer for backward andforward adjustments relative to said slot.

2. In a blind stitch sewing machine, the comits nose directly in frontof the slot in said foot,

a ridge forming element for projecting a ridge of hemmed materialupwardly through the slot in the foot and into the path of the needle,and means for supporting the hemmer for vertical adjustments relative tothe foot.

3; In a blind stitch sewing machine, the combination with a stationarypresser foot having a slot extending rearwardly from the front endthereof, of a feeding means co-operating with the foot to feed thematerial rearwardly, a stitch forming mechanism including areciprocatory needle disposed above the slot in the foot, a hemmerlocated in front of the foot and having its nose directly in front ofthe slot in said foot, a ridge forming element for projecting a ridge ofhemmed material upwardly through the slot in the foot and into the pathof the needle, and means for supporting the hemmer for backward andforward adjustments relative to said slot and for vertical adjustmentsrelative to the foot.

4; In a blind stitch sewing machine, the combination with a stationarypresser foot having a slot extending rearwardly from the front endthereof, of a feeding means co-operating with the foot to feed thematerial rearwardly, a stitch forming mechanism including areciprocatory needle disposed above the slot in the foot, a hemmerlocated in front of the foot and having itsnose directly in front of theslot in said foot, a ridge forming element for projecting a ridge ofhemmed material upwardly'through the slot in the foot and into the pathof the needle, and means for. supporting the hemmer for lateraladjustments relative to'said slot. v

5. In a blind stitch sewing machine, the combination with a stationarypresser foot having a slot extending rearwardly from the front endthereof, of a'feedingmeans co-operat'ingwith the foot to feed thematerial rearwardly, a stitch forming mechanism including areciprocatory' needle disposed above the slot in the foot, ahemmerlocated in front of the foot and having its nose directly in front ofthe slot in said foot, a ridge forming element for projecting a ridge.of hemmed material upwardly through the slot in..the foot and into thepath of the needle, and means for supporting the hemmer for backward andforward and lateral adjustments relative to said slot.

6. ma blind stitch sewing machine, the combination with a stationarypresser foot having a slot extending. rearwardly from the front endthereof, of a feeding means co-operating with the foot to feed thematerial rearwardly, a stitch forming mechanism including areciprocatory needle disposed above the slot in the foot, a hemmerlocated in front of the foot and havingits nose. directly in front ofthe slot in said foot, a ridge forming element for projecting a ridge ofhemmed'material upwardly throughthe slot "in the foot and into the pathof the needle,

and means for supporting the hemmer for backward and forward and lateraladjustments relative to said slot and for vertical adjustments relativeto the foot.

7. In a blind sitch sewing machine, the combination with a frameincluding a standard, an overhanging arm extending therefrom, astitching head carried by the outer end of said arm, and a work armextending from the standard and having its free end terminating underthe stitching head; of a stationary presser foot fixed to the stitchinghead and provided with a rearwardly extending slot; a feeding meansco-opcrating with the foot to feed the material rearwardly; a stitchforming mechanism including a reciprocatory needle disposed above theslot in the foot; a work plate disposed above the work arm; a hemmermounted on the work plate in front of the foot and having its noselocated directly in front of the slot in the presser foot; and a ridgeforming element mounted on the work arm for projecting a ridge of hemmedmaterial upwardly through the slot in the foot and into the path of theneedle.

8. In a blind stitch sewing machine, the combination with a frameincluding a standard, an overhanging arm extending therefrom, astitching head carried by the outer end of said arm, and a work armextending from the standard and having its free end terminating underthe stitching head; of a stationary presser foot fixed to the stitchinghead and provided with a rearwardly extending slot; a feeding meanscooperating with the foot to feed the material rearwardly; a stitchforming mechanism including a reciprocatory needle disposed above theslot in the foot; a work plate disposed above the work arm; a hemmermounted on the work plate in front of the foot and having its noselocated directly in front of the slot in the presser foot; a ridgeforming element mounted on the work arm for projecting a ridge of hemmedmaterial upwardly through the slot in the foot and into the path of theneedle; and means for supporting the work plate on the frame forbackward and forward adjustments.

9. In a blind stitch sewing machine, the combination with a frameincluding a standard, an overhanging arm extending therefrom, astitching head carried by the outer endof said arm, and a work armextending from the standard and having its free end terminating underthe stitching head; of a stationary presser foot fixed to the stitchinghead and provided with a rearwardly extending slot; a feeding meanscooperating with the foot to feed the material rearwardly; a stitchforming mechanism including a reciprocatory needle disposed above theslot in the foot; a work plate disposed above the work arm; a hemmermounted on the work plate in front of the foot andhaving its noselocated directly in front of the slot in the presser foot; a ridgeforming element mounted on the work arm for projecting a ridge of hemmedmaterial upwardly through the slot in the foot and into the path of theneedle; and means for supporting the work plate on the frame forvertical adjustments.

10. In a blind stitch sewing machine, the combination with a frameincluding a standard, an overhanging arm extending therefrom, astitching head carried by the outer end of said arm, and a work armextending from the standard and having its free end terminating underthe stitching head; of astationary presser foot fixed toxthe stitchinghead and provided'with' a rearwardly extending slot; a feedingmeanscooperating with the foot to feed the material rearwardly; a stitchforming mechanism including a reciprocatory needle disposed above theslot in the foot; a work plate disposed above the work arm; a hemmermounted on the work plate in front of the foot andhaving its noselocated directly in front of the slot in the presser foot; aridgeforming'element mounted on the work arm for projecting a ridge ofhemmed material upwardly through the slot in the foot and into the pathof the needle; and means for supporting the work plate on the frame forbackward and forward and vertical adjustments.

11. In a blind stitch sewing machine, the combination with a frameincluding a standard, an overhanging arm extending therefrom, astitching head carried by the outer end of said arm, and a work armextending from the standard and having its free end terminating underthe stitching head; of a stationary presser foot fixed to the stitchinghead and provided with a rearwardly extending slot; a feeding meansrcooperating with the foot to feed the material rearwardly; a stitchforming mechanism including a reciprecatory needle disposed above theslot in the foot; a work plate disposed above the work arm; a hemmermounted for lateral adjustments on the work plate in front of the footand having its nose located directly in front of the slot in the presserfoot; a ridge forming element mounted on the work arm for projecting aridge of hemmed material upwardly through the slot in the foot and intothe path of the needle; and means for supporting the work plate on theframe for backward and forward adjustments.

12. In a blind stitch sewing machine, the combination with a frameincluding a standard, an overhanging arm extending therefrom, astitching head carried by the outer end of said arm, and a work armextending from the standard and having its free end terminating underthe stitching head; of a stationary presser foot fixed to the stitchinghead and provided with a rearwardly extending slot; a feeding meanscooperating with the foot to feed the material rearwardly; a stitchforming mechanism including a reciprocatory needle disposed above theslot in the foot; a work plate disposed above the work arm; a hemmermounted on the work plate in front of the foot and having its noselocated directly in front of the slot in the presser foot; a ridgeforming element mounted on the work arm for projecting a ridge of hemmedmaterial upwardly through the slot in the foot and into the path of theneedle; horizontal pivots supporting the end of the work plate oppositethe presser foot on the standard; and means connecting the work plateand work arm for vertically adjusting the plate relative to the presserfoot and the work arm.

13. In a blind stitch sewing machine, the combination with a frameincluding a standard, an overhanging arm extending therefrom, astitching head carried by the outer end of said arm, and a work armextending from the standard and having its free end terminating underthe stitching head; of a stationary presser foot fixed to the stitchinghead and provided with a rearwardly extending slot; a feeding meansco-operating with the foot to feed the material rearwardly; a stitchforming mechanism including a reciprocatory needle disposed above theslot in the fcot; a work plate disposed above the work arm; a hemmermounted on the work plate in front of the foot and having its noselocated directly in front of the slot in the presser foot; a ridgeforming element mounted on the work arm for projecting a ridge of hemmedmaterial upwardly through the slot in the foot and into the path of theneedle; horizontal pivots supporting the end of the work plate oppositethe presser foot on the. standard; and means connecting the Work plateand work arm for vertically adjusting the plate relative to the presserfoot and the work arm, said connecting means including a headed anchorpost disposed under the work plate and secured to the work arm, and a'vertically adjustable post mounted on the work plate and having aperipheral groove on its lower end engageable with the head of theanchor post.

14. In a blind stitch sewing machine, the combination with a frameincluding a standard, an overhanging arm extending therefrom, astitching head carried by the outer end of saidarm, and a work armextending from the standard and having its free'end terminating underthe stitching head; of a stationary presser foot fixed to the stitchinghead and provided with a rearwardly extending slot; a feeding meansco-operating with the foot to feed the material rearwardly; a stitchforming mechanism including a reciprocatory needle disposed above theslot in the foot; a work plate disposed above the work arm; a hemmermounted on the work plate in front of the foot and having its noselocated directly in front of the slot in the presser foot; a ridgeforming element mounted on the work arm for projecting a ridge of hemmedmaterial upwardly through the slot in the foot and into the path of theneedle; horizontal pivots supporting the end of the work plate oppositethe presser foot on the standard; and means connecting the work plateand work arm for vertically adjusting the plate relative to the presserfoot and the work arm, said connecting means including a headed anchorpost disposed under the work plate and secured to the work arm, and avertically adjustable post mounted on the work plate and having aperipheral groove on its lower end engageable with the head of theanchor post, the work plate being bodily adjustable forwardly andrearwardly at its pivots, and the anchor post being at one side of theadjusting post.

15. In a blind stitch sewing machine, the combination with a stationarypresser foot having a slot extending rearwardly from the front endthereof, of a lower feeding means co-operating with the foot to feed thematerial rearwardly, a stitch forming mechanism including areciprocatory needle disposed above the slot in the foot, a hemmerlocated in front of the foot and having its nose directly in front ofthe slot in said foot, and a ridge forming element for projecting aridge of hemmed material upwardly through the slot in the foot and intothe path of the needle, said feeding means including a i-motion feed dogengageable with the fabric adjacent the hem and a vertically yieldable4-motion auxiliary feed dog engageable with the hem.

CHARLES W. MUELLER.

